Grate.



T. GRIEVE.

GRATE.

APPLICATION FI'LED 12 113.10, 1910'.

Patented Aug. 29, 1911.

T. GRIEVE.

Patented Au 29, 1911'.

5 SHEETS-SHEET 2.

T. GRIEVE.

. GRATE. APPLICATION FILED 23.10, 1910;

Patented Aug. 29, 1911.

6 SHEETS-SHE'S? 3.

illlIlTll JLQ lllllllllllM-IIIIIIIIIIHIIIIW ilLLLlIIIIl Q.

GBATE.

APPLICATION FILED I'EB.10, 1910.

Patented Aug. 29, 1911.

5 SHEETS-SHEET 4.

Z-Zy I? Wows l:

T. GRIEVB.

GRATE. APPLICATION FILED IBB.10, 1910. I

' Patented Aug. 29, 1911.

5 SHEET-SHEET 5.

WX WESSL S openings at the bottom of the grate provides I nooaaoo.

THOMAS GRIEVE, OF PERTH AMBOY, NEW JERSEY, ASSIGNGR TO THE GBIEVE GRATECOMPANY, OF NEW YORK, N. Y.,

A GDRPGRATIQN OF NEW YORK.

GRATE.

' To aZZ'w/wm it may concern.

Be it known that I, THOMAS Garnvn, a citizen of the United States,residing at Perth Amboy, New Jersey, have invented fuel, and for thispurpose the orifices "through said grate are arranged to obtain -ing anddiffusing said air throughout the fuel.

the mostthbrough andcomplete diffusion of air throughout said fuel bed,so as to pro" duce a uniform area of effective combustiou throughout theentire surface of said grate.

My object is to have a grate with a restricted area for admission of airto the fuel bed, combined with a strong forced draft, and to prevent theescape of air around the grate or fuel bed, so as to control aseffectively as possible the supply and distribution of the air into thebed of fuel.

For best results the. perforations through the grate should be evenlyspaced from one another and arrangedto supply air equally to theintervening dead space, and in burning fuel of poor combustiblequality,'such as anthracite screenings, dust, breeze (Waste.

coke), etc, the perforated area should be small in comparison to thesurface area of the grate, and sufficient air supplied to the fuel by anincreased forced draft. The'perforat-ions of the grate preferably have acircular form at the lower side of thegrate tapering upwardly intonarrower elongated openings at the upper surface thereof. Thisdistribution of comparatively large ClIClllfiIf an extensive gatheringagency for the entering air, which is concentrated and driventhrough'the smaller elongated outlets at the surface with an injectoreffect for assisting the action of the forced blast in spread- To obtainthe hill effectiveness of the draft beneath the fuel bed, the sides ofthe grate are preferably locked; or sealed the Specification of LettersPatent.

Patented Aug. as, ism.

Applicatlcn filed February 10, 1910. 7 Serial No; 543,044.

side walls-of the furnace, whereby leakage of air around the outside ofthe fuel bed is prevented, and accurate control of the airpassingthrough the fuel bed is obtained. The air beneath the grateparticularly when a forced draft is employed, has a tendency to creepalong the walls of the furnace between the outside edges of the grate,which not only has an objectionable efiect on the fire, but this actionsoon causes the furnace walls to disintegrate, firumble away, and formeven larger 'e'scaping passageways, until the arch or wall of thefurnace must be rebuilt. Therefore it is the object of my invention toboth prevent this crumbling away of the furnace walls and to provide aconstruction of grate which does not easily deteriorate or wear away.under the great heat to which it is subjected, whereby the longevity ofthe entire furnace is greatly in creased. Further advantages of thisconibination and novelifeatures of construction will be hereinafter morefully described, and the scope of the invention particularly pointed outin the appended claims.

Referring to the accompanying drawings which show a preferred embodimentof my invention; Figure 1 is a longitudinal section of the entire grate;Fig. 2 1s a partial plan of the. same; Fig. '3 is a detail of the rockerbar bearing along YY of Fig. 2 Fig. 4 is a similar detail along line X-Xof Fig. 2; Fig. 5is a front end view of the grate; Fig. 6 is a. sectionacross the furnace along A-A Fig. 2; Fig. 7 is a detached plan view ofone grate section; Fig. 8 is an elevation of the same partly in section;Fig. Sis a cross section 'of the same along BB of Fig. 7; Fig. 10 is aperspective view of a rocker bar; Figs. 11 and 12 are perspective viewsof the bearing details; and Figs. 13, 14 and 15 are details showing theconfiguration of the grate perforations; Fig. 16 is a fragmentary viewof the sliding cover for the dumping bar; Fig. 17 is an enlarged planView of a portion of a grate section showing more accurately therelative size and arrangement of the elliptical perforations; and Fig.18 isa perspective view of the entire grate showing themeans forsupplying a forced draft thereto.

Referring more particularly to the drawings, 1 indicates the front"Wall, 5i, l the side walls and i the rearwall of the furnace. Theentiregrate coinprises a frame ago shown.

- 3; Sindicate the side supporting bars, and

3 the rear supporting barof the frame, all

of which a' front supporting bar or dead.

plate 2 is mountedadjacent the front wall. of the furnace. For thesake'of convenience.

this dead plate is preferably constructed in three sections, 2, 2, 2 asshown in Fig. 5,"

all rivetedtogether. The parts ,2, 2 are supporting stanchion's' asprovided 4 with 'of'which' preferably have a laterally extending'flange: 3 as shown in Figs. 1 and,6,'

embedded in the 'masonry of the walls; A

. longitudinal central supporting bar 5 connects the front and rear endbars, and although inf'the construction shown. only-one if'of theselongitudinal bars is provided, is

. understood that the size of the "furnace may be extended so asto havea pluralityof said bar's if desired. Oneor more supporting posts-'-16-.may be provided asshown for this central bar 5.. One or moretransverse strengthening-bars ,4=0 con'nect' the side bars and "thecentral bar and these may also form 'abutments for theadjacent ends ofthegrate sections, as -willbe hereinafter described.

"'. "1ransversely mounted in bearings 12 between the longitudinal barsis a rocking bar 8 having trunnions 9 and 10-for turning in thebearings, see Fig. 10. Secured to each bar 8' is an operating arm 11- asshown and "these arms may be secured to a common It is'often desirabletoremove thisrocking operating rod such as 17 for rockingall of theconnected grate sections simultaneously.

. bar from the grate, 'such' as for repair or .renewal, andfor thispurpose I have shown a preferable construction of bearing whichwillallow this removal in Figs. 3 and 4. The trunnion of the rocking barrests in the bearing seat- 12' and is held therein by plug or block 13',which is shown in detail in Fig.

12. A sliding key 14: shown in Fig. 11 with beveled edges is insertedabove the block 13 to form a' lock therefor. The bearings along thecentral longitudinal bar 5 are preferably.

- as shown in .Fig. 3, wherein the key 14 extends clear'across the barbut the side bars are preferably provided with bear ngs such as, shownin Fig. 4:, where the key l-it can only; be inserted at one end.

Detachably -mount'ed upon each of the rocking bars are one or-more gratesections I55.

such as shown in Figs. 7, 8 and 17. These grate sections have dependingside-ribs 6 {S -shown inFigs. 1, 8 and 9, andthese ribs are cut away attheir center-to provide ani: upwardly tapering notch so that they mayembrace the rocker'bar 8-as shown in F1 8. A bolt 21 and plate 22 may beused to detachably secure the grate section to the rocking bar. Ipreferably mount the grate sections upon this rocking bar away Lrointheir tral line or in any other way,

ling

larlyf toFig. -1'7, the perforations may be; Icoiisidered lying inseveral difi'erent;

which will put them out of balance so that sections, so that the gratesections when in horizontal position'with their ends resting against thetransverse bars, will fit the same closely and form' a substantiallyair-tightclosure. It will be observed in Fig. 1 that the adjacentportion'" of the dead plate 2*, as well as the rear end'plate 3 is alsobeveled to fit the ends of the grate sections.-

Along one or both longitudinalsides of the grate sections is, preferablyformed a lateral projecting flange 6 which serves as the abutting edgebetween-the adjacent sections.

Each of the grate sections is perforated uniformly throughout itssurface, and the deadplate2, as well as the transverse bars 40, areperforated in the same manner, while the abutting side edges 6 of thegrate sections and the side'supporting bars 3,- 3 are. provided withsemi-circular matching .re-

cesses 7 as shown to complete this uniform distribution of air holes.tions are preferably formed as shown in These perfora- Figs. 13, 14: and15, that is, tapering from the bottom toward the top'and also-having acircular shape at the bottom with a substantiallyelliptical or elongatedshape atthe top. This form of perforationhas been found in practice tospread the air passing 'therethrough into a narrow fan-like sheet whichmore completely difiuses throughout the fuel bed than when the air comesup throughaperfectly round'hole.

- As shown'moreclearly in Figs. 7 17 of the drawings, the. perforations7 are preferably-arranged in accordance with a regular constructionaldesign, the arrangement being such that the center of each perforationis equally distant fI' OIDBELCh adjacentperforation. The perforationsare alsodisposecl in parallel rows, the perforations of each row beingstaggered with those of adjacent rowsand since the centers, of alladjacent per-j forations are v equidistant, the design of thisarrangement is such that lines drawn through the centers of mutuallyadjacent perforations 'would form a series of adjacent equilateraltriangles. This arrangement is importantas providing a very compactarrangement of perforations to obtain uniform distribution of air-spacedarea and atthe same time preserving the structural strength of the gratebar. Since the webbing between theair perforations is of substantiallythe same Width and thickness throughout, the.

liability of. weak places subject; to crackis avoided. Referring moreparticur w r along .l1ne

a tt-n fo' ht j distance between adjacent perforations. This arrangementI have found provides an even difiusion of the an throughout the fuelbed;

and produces a uniform areaof effective Combustion throughout thesurface of lsaid grate; By a uniform 'area of efi'ective combustion ismeant thatthe fuel is equally Well consumed over all parts of said gratehaving no partially burned black spots as is the case With the ordinarygrate, which has no such even distribution of air supply.

In Fig. 18 is illustrated the preferred means for introducing the forceddraft be neath the grate, in which 37 indicates an opening through thebottom of the furnace, said opening 37 communicating with a conduit 38leading from an ordinary fan or blower 39 which supplies the draft.

I provide-a 'fine distribution of'comparatively small-sized openings atthe surface of the grate, rather. than a coarse distribution of largeopenings, since with a forced draft of air under high pressure comingthrough large openings the fuel bed is apt to be blown to pieces. Forbest results, therefore, my perforations are sufliciently restricted insize to prevent the fuel bed from being broken up and disposed closelyenough together to supply all parts of the fuel evenly, the combinedarea of the perforations being less than one-sixth or 16%70 of the totalsurface area of'said grate usually from 6% to 8% of said area.Furthermore, my perforations as shown are arranged with their longeraxes transversely of the lengthwise direction of said grate section, or,in other words, the direction of the elongation of said perforations isacross the shorter side of said grate section. This arrangement addsmaterially to the structural. strength ofthe grate section, and to alarge extent pre-' vents the cracking-of the section along, its

length.

Byreference to Figs. 1, 2 and 6, it will be observed that the sides andrear end of the grate are locked or sealed into the side and back wallsoffthe furnace by the flanges 3, being embedded-into the masonrythereof. The air at the sides of the grate can therefore not find its.wayup along the side walls is employed.

of the furnace outside the edges of the fuel bed and mingle with theproducts of com bustion to cool the fire,

through the orifices formed by the matching 7* at the abutting edgessemicircular recesses of the grate section and side bars 3, 3 and enterthe bed of fuel. Since these bordering orifices are a part of theregular design of. the perforated area and of equal size with,

the other perforations, thereis no greater tendency for the air to passthrough .the

bordering portions of the fuel bed than through any other portion. Inother words, all of the air passing through, the grate \passes throughthe bedof fuel and is distributed uniformly throughout the same.

- At the front of the furnace is the usual op crating crank 22 for the-dumping bar 17,

which bar extends through the furnace front as shown. The slottedopening in the furnace front is sealed by a plate 19 which isslidablymounted at oneuside of the furnace but mustpass up front by meansofstuds 2O engaging ,end

slots .21 in said plate. The plate .has'an opening which closely fitsthe bar 17 and therefore vertically reciprocates with the up,

and down movement of said bar, but has no longitudinal movement awayfrom the fur-. nacefront. The opening is thus kept -cov-' ered at alltimes. This arrangement is for the purpose of preventing the escape ofair from beneath the grate when the forced draft What I claim is: 1. Agrate comprising a stationary sup- "porting frame composed of side barsand end bars having flanges adapted to 'be embedded in the Walls of thefurnace, transverse and longitudinal supporting bars connecting saidside and end bars respectively, several perforated grate sectionspivotally mounted in said longitudinal bars, the abutting edges of saidgratesections and side longitudinal bars being oppositely recessed tomatch and form orifices, the opposite ends of said sections adapted torest against said adjacent transverse supporting bars and being beveledin the same direction, said transverse supporting bars also beingbeveled to fit the supporting ends of said sec: tions.

, l 't 2. A grate for furnaces comprlsing a sup-- porting frame havingside bars and end bars with flanges adapted to be inserted in themasonry of said furnace Walls for forming a sealed joint, longitudinaland transverse supporting bars .connecting said opposite end bars andopposite side bars respectively, several grate sections pivotallymounted on saidlongitudinal supporting bars to form a "support for afuel bed, said grate sections v having their ends resting onsaid-transverse supporting bars, the abutting edges of said supportingbars and grate sections 'bemg .beveled to fit closely, each of saidgrate sections as Well as said transversesupporb,

ingv-bars haying; similar perforations uni;

form ly. distributed throughout the same, and the adjacent edges of saidgrate sections as well as ,the edges of said longitudinal su portingbars being recessed to match .w'alls of a furnace, its perforationsbeing circular. in shape at the lower side of said grate and elongatedin shape at the upper surface thereof, in combination with means forforcing a draft of air therethrough, the

sides of said grate beingsealed' t0 the walls ofsaid furnace to preventthe passing of air between the lateral edges of said grate and saidfurnace walls.

grate and elongated in shape at the upper surface thereof, the center ofeach perforaacent perforation, in combination with means for forcing adraft of. air therethrough, the sides of said grate being sealed to thewalls of said furnace to prevent the passing .of air between the lateraledges of said grate and said furnace walls.

5. A perforated grate mounted within the walls of the furnace, itsperforations bein' circular vin shape at-the lower slde OfSfll grate andtapering upwardly. to narrower elongated openings at the surfacethereof, in combination with means for forcing a draft flanges at itslateral edges embedded in the walls of said furnace to preventthepassing "and said furnace walls. o

a Signed at New york city, this th day O 4; Aperforated grate mountedwithin the," i 3 walls of a furnace, its perforations being,

' circular in shape at the lower side of said Jannary,191()m c 3 v 1THOMAS "GRI'EVE;

s a, l a I g 1 Begmnrofl MIRVIS,

NATHAN V Ers 'mmi tion being equidistant from the center of each of airtherethrough, said grate havingofair between the lateral edges ofsaidgrate.

